Wrench



Feb. 1, 1938. J. R. BITTNER l 2,107,231 l* WRENCH Filed Feb. 2, 1937 Patented Feb. 1, 1938 UNITED STATES align PATENT OFFCE WRENCH K. Wilson Application February 2, 1937, Serial No. 123,653

z claims.

This invention relates to improvements in wrenches, and more particularly to wrenches of the general character shown in U. S. Patent No. 1,504,153.

One object of the invention is to provide a Wrench of this type which shall be more efcient functionally and more durable than the wrenches of the prior art.

Another object of the invention is to provide a Wrench of generally improved structural characteristics and one that is more susceptible to manufacture at a reasonably low expense.

The invention further resides in certain structural and mechanical details hereinafter described and illustrated in the attached drawing, in which:

Figure 1 is a side View of a wrench made in accordance with my invention, a portion of the wrench being cut away to disclose certain structural details;

Fig. 2 is a fragmentary front view of the wrench;

Fig. 3 is a section on the line 3-3, Fig. 1;

Fig. 4 is a detached perspective View of the relatively xed jaw element;

Fig. 5 is a View in perspective of the terminal end of the shank to which the relatively fixed jaw is attached;

Fig. 6 is a fragmentary sectional view illustrating a function of the wrench, and

Fig. 7 is a similar View illustrating a further detail of operation.

With reference to the drawing, a wrench made in accordance with my invention comprises a shank I, a relatively fixed jaw 2 at one end of the shank, and a carrier 3 which is slidable longitudinally of the shank and upon which is mounted a relatively movable jaw 4. The inner side of the shank I, i. e., that side from which the jaws 2 and 4 project, is provided with a series of ratchet teeth 5, and mounted on the carrier 3 is a pawl B which by engagement with the teeth 5 of the shank is adapted to maintain the carrier in adjusted position longitudinally of the shank. The sliding movement of the carrier on the shank away from the fixed jaw is limited by means for example of a screw I in the carrier and a screwengaging pin Illa on the shank.

In the present instance, and in accordance with my invention, the end of the shank I to which is attached the relatively xed jaw 2, is provided at each side with a transverse recess or Way l, see Fig. 5, which are adapted to receive spaced extensions 8, 8 at the rear of the jaw 2, these extensions snugly ltting the ways I and closely embracing the opposite faces of the shank. Registering apertures 3 and 9o; are provided in the shank and in the extensions 8, 3 of the jaw for reception of a pin l I which positively secures the jaw 2 to the shank. It will be noted that the outer extremity I2 of the shank at the inner side is provided with an outwardly curved surface I3 which ts a reversely curved seat I4 on the jaw 2, thereby affording an extended bearing between the shank and the jaw directly opposing the line of normal thrusts. The aforedescribed construction provides a highly elcient detachable jaw assembly of great strength, and has the further advantage of facilitating the process of manufacture.

The carrier 3 is of U-shape, as illustrated, and embraces the rear side and both faces of the shank, The jaw t is pivotally mounted upon a pin I which extends between and is riveted in the flanges of the carrier. At its inner end the jaw ll is provided with a tail extension I3, which is adapted to bear against the inner side of the shank I, and this tail I6 is provided with a rounded portion II which as hereinafter described functions as a floating fulcrum for the jaw against the shank. The pawl 6, in the present instance, is pivotally mounted intermediate its ends upon a pin I8 which extends between and is riveted in the anges of the carrier 3. The upper extension I 9 of the pawl is provided at its inner side with a projecting boss 2l which supports the outer end of a coiled spring 22, the inner end of this spring bearing against the tail portion I6 of the jaw 4. When thus interposed under compression between the upper end I9 of thepawl lever and the tail I6 of the jaw, the Spring exerts pressure to resiliently force both the tail I6 and the pawl 6 against the inner side of the shank. By pressing the extension I9 of the pawl, as shown in Fig. 7, the pawl proper is retracted from the teeth of the shank I and the carrier 3 is thereby freed for adjustment on the shank. Preferably the teeth 5 of the shank are so formed that the pawl 6 may slide over these teeth when the carrier 3 is forced upwardly on the shank toward the jaw 2.

The spring 2| functions also through the tail I6 of the jaw II and through the pawl E to maintain the carrier 3 in a normal position as shown in Fig. 1 wherein the carrier bears flatly against the outer side of the shank. It is apparent, however, that aside from this resilient pressure exerted by the spring 2|, the carrier is free for limited movement away from the outer side of the shank. Such movement of the carrier 3 with respect to the shank is shown, for example, in Fig. 6, wherein it will be noted that by reason of a movement of the shank I around a pipe 23 engaged between the jaws 2 and 4 and in the direction indicated by the arrow, the carrier has Vbeen tiltedV upon the shank from its normal position, this tilting occurring around the lower edge 3a of the carrier as a fulcrum. It is apparent that in this tilting of the carrier 3 the pivot pin I5 supporting the jaw 4 has been moved toward the relatively fixed jaw 2, and that the movable jawy 4 has been correspondingly moved in the same direction. It will be noted also that in this movement of the jaw 4 from the normal position, as shown in Fig.Y l, toward the position in which it is shown in Fig. 6, there has been an additional movement of the jaw 4 about its pivot I5, and that accordingly the total movement of the `jaw 4 toward the jaw 2, during which the pipe 23 has been clamped with increasing pressure, is compounded of the movement of the jaw 4 about its pivot and of the movement of the carrier 3 around the fulcrum point 3a. It Awill ybe noted further that at all times during this movement, the rounded portion I1 of the tail I6 of the jaw 4 is in rm contact with the inner side of theY shank. By means of this compound movement, the effective pressure of the jawsupon the pipe 23 isV materially increased over what would, result from a simple movement of Vthe jaw on its pivot, and at the same time the stresses imposed upon the jaw 4, the carrier 3, and the pawl 6, and upon the pins I5 and I8 which support the said jaw andV pawl, are in eiect distributed throughout the as- Y sembly, and are not imposed solely upon the pins Vwhich carry the jaw and the pawl as in those prior devices wherein the carrier is mounted upon radius, and as the jaw Wedges inwardly'under the pipe the strain, which falls entirely on the pivot pin, isY severe.Y Ina wrench constructed in 'ac- Yc'ordanee with my invention, a part of the movable jaw action occurs on the relatively long radius Ycentering at the lower edge 3a Vof the'carrier, and the action on the shorter radius is materially reduced.Y This 1fact, coupled with the continuous solid pivotal bearing of the movable jaw upon the inner side of the shank, results not only in the aforedescribed reduction in the direct strains imposed upon the pivot pins and in a more uniform distribution of the strains, but also, by reason of the relatively great scope of movement of the movable jaw toward the xed jaw, avoids al1V tendency of the jaws to slip on the pipe.

I claim: I

1. A wrench comprising a shank having a lateral jaw at one end projecting from the inner side of the shank, said shank having teeth onr said inner side, a U-shaped carrier slidable on the shank, said carrier embracing the outer side and faces of the shank and being free for transverse movement away from the said outer side, a movable jaw pivoted on said carrier for movement toward and away from the shank and having a tail end portion extending beyond the pivot and adapted to engage the innerA side of the shank, a thumb lever pivoted intermediate its ends to the carrier and formed at one end as a pawl for engagement with the teeth of said shank to retain the carrier in adjusted position longitudinally of the shank, and a spring interposed betweenV the other end ofV said lever and thev edge of said movable jaw and exerting pressure to force both said tail and said pawl against the inner sideof the shank and tending also to resiliently retain the carrier in a normal position of engagement with the outer side of the shank.

2. A wrench comprisinga shank having a lateral jaw atV one end projecting from the inner side of 'the shank, said shank having teeth on said inner side, a .U-shaped carrier slidable on the shank, said carrier embracing the outer side and tudinally of the shank, and resilient meansforl Vnormally retaining the tail of said movable jaw and said pawl in engagement with the inner side of said shank,.said resilient means tending also to resiliently retain thecarrier in a normal position of engagement with the outer side of'the shank. n

Y JOSEPH R. BI'I'INER. 

